Short Procedure Units (also known as day surgery, ambulatory surgery, etc.) are one of the numerous alternatives to inpatient care that have received wide attention during the last several years. It is estimated that inpatient surgery accounts for 60 percent of all hospital expenditures and 25 percent of all health expenditures. Achievement of reductions in this costly aspect of health care may have a substanstial impact on health expenditures. The rapid proliferation of Short Procedure Units has been characterized by adoption of diverse organizational structures, medical protocols and activities. Literature, while documenting cost savings for individual units, report a wide variance in performance. Currently, no information is available which would serve to assess the exact magnitude of cost savings to be achieved and the factors which affect performance levels. The intent of this work is to examine SPUs in one region to assess the current status of SPUs with respect to organizational and operational characteristics, to evaluate cost savings, and to investigate factors which influence performance. The study utilizes a retrospective design with pre- and post-SPU comparisons for analysis of case cost impact. The relationship of organizational and operational features of SPUs, obtained through interviews with unit administrators, will be linked to performance levels observed.